Network diagnostics and management are becoming more prominent as the number of networks grows. Industry has primarily focused network diagnostics and management on wired networks in general, and on wide area Internet failures in particular. However, many companies are evolving towards enterprise wireless networks to become more productive. As a result, the problems associated with securing and managing wireless networks have become more prominent.
Industry has provided some commercial offerings in the area of wireless network management using two common approaches. The first common approach is to rely on Access Points (APs) for monitoring wireless networks. The second common approach is to use dedicated and often expensive custom hardware sensors for monitoring the network. The companies that offer products in these areas rarely discuss the mechanisms they use to detect problems. For example, there are many different levels of sophistication that one can provide when solving the security problems of rogue wireless equipment, but companies do not disclose their mechanisms used to implement their solutions.
The approach that relies on APs for monitoring wireless networks is certainly cost effective, but it has several limitations. First, an AP can not easily monitor multiple channels, or associate with other nearby APs, since the AP's primary function requires it to spend most of its time on one specific channel serving associated clients. Second, the APs usually have limited CPU power and memory resources so it is not practical to poll APs (e.g., issued SNMP (Simple Network Management Protocol) queries) too frequently. Third, the level of detail that typical commercial APs provide with their response (i.e., through their SNMP interfaces) is quite limited. Fourth, APs tend to be closed platforms so one cannot load and run third-party code on an AP, making it difficult to quickly deploy new functionality. Finally, an AP only provides a view of one end of the wireless communication, so an AP-based solution can not be used to detect problems such as radio frequency (RF) holes or excessive interference that primarily affect the client end of the communication.
Another common approach of using dedicated hardware sensors for RF monitoring deploys special sensor nodes throughout the wireless network. Industry has also augmented the AP-based monitoring by deploying these special sensor nodes throughout the organization. However, the specialized sensors are quite expensive.
The behavior of the wireless network is dependent on the physical location of the network hardware. Due to the nature of wireless signal propagation, the physical location of both the transmitter and the receiver may have a large influence on the performance observed by end-users. Specifically, the probability of frame loss, and the data rate selected for frame transmission can be impacted by the locations of the transmitter and the receiver. By determining the location of the transmitter, the network administrator can take concrete steps to improve the reliability and performance of their wireless networks.
Many wireless location estimation systems require a mapping step whereby an administrator moves throughout the area being covered by the location system to create a “signal propagation profile” of the environment. This profile needs to be updated at regular intervals to ensure that it reflects the current environmental conditions. Thus, current wireless location estimation systems require significant human administration resources.